1679 interview questions for Back-end developer (2026)

Medium

118 votes4652 runs

6 comments

Understanding the differences between `map()` and `forEach()` methods in JavaScript

Web developer

Anonymous authorat Jan 18, 2024

Easy

55 votes3751 runs0 comment

Write a SQL query to retrieve the list of employees with a salary greater than 5100.

Back-end developer

sql

select

where

Anonymous authorat Mar 30, 2023

Medium

50 votes4267 runs4 comments

Write a JavaScript function that fetches data from an API and logs it to the console.

Web developer

promises

async

Anonymous authorat Mar 28, 2023

Easy

44 votes2281 runs1 comment

Write a Python function that returns the factorial of a number.

Back-end developer

recursion

Anonymous authorat Mar 28, 2023

Easy

39 votes3342 runs

13 comments

Write a Java program that prints 'welovedev'.

Full stack developer

strings

variables

Pierreat Sep 19, 2022

Easy

39 votes2341 runs1 comment

Explain the difference between the `include` and `require` functions in PHP.

Back-end developer

functions

errors

Anonymous authorat Mar 24, 2023

Easy

32 votes4354 runs

2 comments

Fix the following Javascript loop:

Web developer

loops

conditions

Anonymous authorat Apr 27, 2023

Hard

27 votes2651 runs

1 comment

Write a Python function that prints the elements of a list.

Back-end developer

list

for loop

Anonymous authorat Mar 28, 2022

Easy

26 votes955 runs1 comment

What is the purpose of the Laravel Sanctum tool?

Web developer

laravel

authentication

Damienat Sep 6, 2023

Easy

21 votes3714 runs0 comment

Write a SQL query to insert data into a table

Back-end developer

sql

insert

Anonymous authorat Mar 27, 2023

Easy

21 votes3700 runs0 comment

Select only distinct values in a column using SQL

Back-end developer

sql

distinct

Anonymous authorat Mar 27, 2023

Easy

19 votes3606 runs1 comment

Update a column in an SQL table

Back-end developer

sql

update

Anonymous authorat Nov 7, 2023

Easy

17 votes3675 runs0 comment

Which SQL keyword is used to sort the result of a SELECT statement?

Back-end developer

sql

order by

Anonymous authorat Mar 27, 2023

Hard

17 votes3663 runs

1 comment

How many times is the condition `(a++ < 15)` evaluated in the following code? ```java int a = 3; while (a++ < 15) { if ((a++ % 5) == 0) break; } ```

Back-end developer

loops

control flow

Thomas De verdièreat Dec 16, 2021

Easy

17 votes3232 runs

2 comments

How should a package be named in Java?

Full stack developer

packages

java

Pierreat Sep 19, 2022

Medium

17 votes3058 runs2 comments

A bean with a `session` scope is injected into a bean with a` singleton` scope. What happens when the application starts?

Back-end developer

spring

scope

Anonymous authorat Dec 21, 2021

Medium

17 votes3016 runs0 comment

Explain the prototype scope in Spring

Back-end developer

spring

bean

Anonymous authorat Dec 21, 2021

Easy

16 votes3747 runs1 comment

What is the minimum PHP version for Symfony 5?

Back-end developer

php

symfony

Smaïne Millaniat Dec 3, 2021

Medium

16 votes1002 runs0 comment

What is the best practice to apply in your code to improve the performance of your application?

Back-end developer

performance

gzip

Anonymous authorat Nov 15, 2023

Easy

15 votes4752 runs

5 comments

The certificate variable is not attainable outside the if loop

Web developer

variables

scope

Anonymous authorat Apr 6, 2022

1679 interview questionsfor Back-end developer (2026)

Test your technical skills before an interview of Back-end developer with 1679 corrected questions. Beginner, Intermediate or Expert level.

Understanding the differences between `map()` and `forEach()` methods in JavaScript

Write a SQL query to retrieve the list of employees with a salary greater than 5100.

Write a JavaScript function that fetches data from an API and logs it to the console.

Write a Python function that returns the factorial of a number.

Write a Java program that prints 'welovedev'.

Explain the difference between the `include` and `require` functions in PHP.

Fix the following Javascript loop:

Write a Python function that prints the elements of a list.

What is the purpose of the Laravel Sanctum tool?

Write a SQL query to insert data into a table

Select only distinct values in a column using SQL

Update a column in an SQL table

Which SQL keyword is used to sort the result of a SELECT statement?

How many times is the condition `(a++ < 15)` evaluated in the following code? ```java int a = 3; while (a++ < 15) { if ((a++ % 5) == 0) break; } ```

How should a package be named in Java?

A bean with a `session` scope is injected into a bean with a` singleton` scope. What happens when the application starts?

Explain the prototype scope in Spring

What is the minimum PHP version for Symfony 5?

What is the best practice to apply in your code to improve the performance of your application?

The certificate variable is not attainable outside the if loop